1. Technical Field
The disclosure generally relates to energy-saving illumination systems, and particularly, to an illumination system containing piezoelectric material which is used to generate electric energy for providing power to a light source of the illumination system.
2. Description of Related Art
A piezoelectric material is a solid material (notably crystals and certain ceramics) which accumulates electrical charge therein in response to applied mechanical strain thereto. The piezoelectric effect is understood as the linear electromechanical interaction between the mechanical and the electrical state in crystalline materials with no inversion symmetry. The piezoelectric effect is a reversible process in that materials exhibiting the direct piezoelectric effect (the internal generation of electrical charge resulting from an applied mechanical force) also exhibit the reverse piezoelectric effect (the internal generation of a mechanical force resulting from an applied electrical field). For example, lead zirconate titanate crystals will generate measurable piezoelectricity when their static structure is deformed by about 0.1% of the original dimension. Conversely, lead zirconate titanate crystals will change about 0.1% of their static dimension when an external electric field is applied to the material. For the one of ordinary skill in the illumination field, how to use the direct piezoelectric effect is the one researching direction.
Therefore, there is a desire to provide an energy-saving illumination system using the direct piezoelectric effect.